Method and apparatus for providing data processing and control in medical communication system

ABSTRACT

Methods and apparatus for providing data processing and control for use in a medical communication system are provided.

RELATED APPLICATIONS

The present application claims priority under §35 U.S.C. 119(e) to U.S.provisional application No. 60/911,869 filed Apr. 14, 2007, entitled“Method and Apparatus for Providing Data Processing and Control inMedical Communication System”, and assigned to the Assignee of thepresent application, Abbott Diabetes Care Inc. of Alameda, Calif., thedisclosure of which is incorporated herein by reference for allpurposes.

BACKGROUND

Analyte, e.g., glucose monitoring systems including continuous anddiscrete monitoring systems generally include a small, lightweightbattery powered and microprocessor controlled system which is configuredto detect signals proportional to the corresponding measured glucoselevels using an electrometer, and RF signals to transmit the collecteddata. One aspect of certain analyte monitoring systems include atranscutaneous or subcutaneous analyte sensor configuration which is,for example, partially mounted on the skin of a subject whose analytelevel is to be monitored. The sensor cell may use a two orthree-electrode (work, reference and counter electrodes) configurationdriven by a controlled potential (potentiostat) analog circuit connectedthrough a contact system.

The analyte sensor may be configured so that a portion thereof is placedunder the skin of the patient so as to detect the analyte levels of thepatient, and another portion of segment of the analyte sensor that is incommunication with the transmitter unit. The transmitter unit isconfigured to transmit the analyte levels detected by the sensor over awireless communication link such as an RF (radio frequency)communication link to a receiver/monitor unit. The receiver/monitor unitperforms data analysis, among others on the received analyte levels togenerate information pertaining to the monitored analyte levels. Toprovide flexibility in analyte sensor manufacturing and/or design, amongothers, tolerance of a larger range of the analyte sensor sensitivitiesfor processing by the transmitter unit is desirable.

In view of the foregoing, it would be desirable to have a method andsystem for providing data processing and control for use in medicaltelemetry systems such as, for example, analyte monitoring systems.

SUMMARY OF THE INVENTION

In one embodiment, method and apparatus for detecting a firsttemperature related signal from a first source, detecting a secondtemperature related signal from a second source, the second sourcelocated at a predetermined distance from the first source, andestimating an analyte temperature related signal based on the first andsecond detected temperature signals, is disclosed.

These and other objects, features and advantages of the presentinvention will become more fully apparent from the following detaileddescription of the embodiments, the appended claims and the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a block diagram of a data monitoring and managementsystem for practicing one or more embodiments of the present invention;

FIG. 2 is a block diagram of the transmitter unit of the data monitoringand management system shown in FIG. 1 in accordance with one embodimentof the present invention;

FIG. 3 is a block diagram of the receiver/monitor unit of the datamonitoring and management system shown in FIG. 1 in accordance with oneembodiment of the present invention;

FIGS. 4A-4B illustrate a perspective view and a cross sectional view,respectively of an analyte sensor in accordance with one embodiment ofthe present invention;

FIG. 5 is a flowchart illustrating ambient temperature compensationroutine for determining on-skin temperature information in accordancewith one embodiment of the present invention;

FIG. 6 is a flowchart illustrating digital anti-aliasing filteringroutine in accordance with one embodiment of the present invention;

FIG. 7 is a flowchart illustrating actual or potential sensor insertionor removal detection routine in accordance with one embodiment of thepresent invention;

FIG. 8 is a flowchart illustrating receiver unit processingcorresponding to the actual or potential sensor insertion or removaldetection routine of FIG. 7 in accordance with one embodiment of thepresent invention;

FIG. 9 is a flowchart illustrating data processing corresponding to theactual or potential sensor insertion or removal detection routine inaccordance with another embodiment of the present invention;

FIG. 10 is a flowchart illustrating a concurrent passive notificationroutine in the data receiver/monitor unit of the data monitoring andmanagement system of FIG. 1 in accordance with one embodiment of thepresent invention.

DETAILED DESCRIPTION

As described in further detail below, in accordance with the variousembodiments of the present invention, there is provided a method andapparatus for providing data processing and control for use in a medicaltelemetry system. In particular, within the scope of the presentinvention, there are provided method and system for providing datacommunication and control for use in a medical telemetry system such as,for example, a continuous glucose monitoring system.

FIG. 1 illustrates a data monitoring and management system such as, forexample, analyte (e.g., glucose) monitoring system 100 in accordancewith one embodiment of the present invention. The subject invention isfurther described primarily with respect to a glucose monitoring systemfor convenience and such description is in no way intended to limit thescope of the invention. It is to be understood that the analytemonitoring system may be configured to monitor a variety of analytes,e.g., lactate, and the like.

Analytes that may be monitored include, for example, acetyl choline,amylase, bilirubin, cholesterol, chorionic gonadotropin, creatine kinase(e.g., CK-MB), creatine, DNA, fructosamine, glucose, glutamine, growthhormones, hormones, ketones, lactate, peroxide, prostate-specificantigen, prothrombin, RNA, thyroid stimulating hormone, and troponin.The concentration of drugs, such as, for example, antibiotics (e.g.,gentamicin, vancomycin, and the like), digitoxin, digoxin, drugs ofabuse, theophylline, and warfarin, may also be monitored.

The analyte monitoring system 100 includes a sensor 101, a transmitterunit 102 coupled to the sensor 101, and a primary receiver unit 104which is configured to communicate with the transmitter unit 102 via acommunication link 103. The primary receiver unit 104 may be furtherconfigured to transmit data to a data processing terminal 105 forevaluating the data received by the primary receiver unit 104. Moreover,the data processing terminal in one embodiment may be configured toreceive data directly from the transmitter unit 102 via a communicationlink which may optionally be configured for bi-directionalcommunication.

Also shown in FIG. 1 is a secondary receiver unit 106 which isoperatively coupled to the communication link and configured to receivedata transmitted from the transmitter unit 102. Moreover, as shown inthe Figure, the secondary receiver unit 106 is configured to communicatewith the primary receiver unit 104 as well as the data processingterminal 105. Indeed, the secondary receiver unit 106 may be configuredfor bi-directional wireless communication with each of the primaryreceiver unit 104 and the data processing terminal 105. As discussed infurther detail below, in one embodiment of the present invention, thesecondary receiver unit 106 may be configured to include a limitednumber of functions and features as compared with the primary receiverunit 104. As such, the secondary receiver unit 106 may be configuredsubstantially in a smaller compact housing or embodied in a device suchas a wrist watch, for example. Alternatively, the secondary receiverunit 106 may be configured with the same or substantially similarfunctionality as the primary receiver unit 104, and may be configured tobe used in conjunction with a docking cradle unit for placement bybedside, for night time monitoring, and/or bi-directional communicationdevice.

Only one sensor 101, transmitter unit 102, communication link 103, anddata processing terminal 105 are shown in the embodiment of the analytemonitoring system 100 illustrated in FIG. 1. However, it will beappreciated by one of ordinary skill in the art that the analytemonitoring system 100 may include one or more sensor 101, transmitterunit 102, communication link 103, and data processing terminal 105.Moreover, within the scope of the present invention, the analytemonitoring system 100 may be a continuous monitoring system, orsemi-continuous, or a discrete monitoring system. In a multi-componentenvironment, each device is configured to be uniquely identified by eachof the other devices in the system so that communication conflict isreadily resolved between the various components within the analytemonitoring system 100.

In one embodiment of the present invention, the sensor 101 is physicallypositioned in or on the body of a user whose analyte level is beingmonitored. The sensor 101 may be configured to continuously sample theanalyte level of the user and convert the sampled analyte level into acorresponding data signal for transmission by the transmitter unit 102.In one embodiment, the transmitter unit 102 is coupled to the sensor 101so that both devices are positioned on the user's body, with at least aportion of the analyte sensor 101 positioned transcutaneously under theskin layer of the user. The transmitter unit 102 performs dataprocessing such as filtering and encoding on data signals, each of whichcorresponds to a sampled analyte level of the user, for transmission tothe primary receiver unit 104 via the communication link 103.

In one embodiment, the analyte monitoring system 100 is configured as aone-way RF communication path from the transmitter unit 102 to theprimary receiver unit 104. In such embodiment, the transmitter unit 102transmits the sampled data signals received from the sensor 101 withoutacknowledgement from the primary receiver unit 104 that the transmittedsampled data signals have been received. For example, the transmitterunit 102 may be configured to transmit the encoded sampled data signalsat a fixed rate (e.g., at one minute intervals) after the completion ofthe initial power on procedure. Likewise, the primary receiver unit 104may be configured to detect such transmitted encoded sampled datasignals at predetermined time intervals. Alternatively, the analytemonitoring system 100 may be configured with a bi-directional RF (orotherwise) communication between the transmitter unit 102 and theprimary receiver unit 104.

Additionally, in one aspect, the primary receiver unit 104 may includetwo sections. The first section is an analog interface section that isconfigured to communicate with the transmitter unit 102 via thecommunication link 103. In one embodiment, the analog interface sectionmay include an RF receiver and an antenna for receiving and amplifyingthe data signals from the transmitter unit 102, which are thereafter,demodulated with a local oscillator and filtered through a band-passfilter. The second section of the primary receiver unit 104 is a dataprocessing section which is configured to process the data signalsreceived from the transmitter unit 102 such as by performing datadecoding, error detection and correction, data clock generation, anddata bit recovery.

In operation, upon completing the power-on procedure, the primaryreceiver unit 104 is configured to detect the presence of thetransmitter unit 102 within its range based on, for example, thestrength of the detected data signals received from the transmitter unit102 or a predetermined transmitter identification information. Uponsuccessful synchronization with the corresponding transmitter unit 102,the primary receiver unit 104 is configured to begin receiving from thetransmitter unit 102 data signals corresponding to the user's detectedanalyte level. More specifically, the primary receiver unit 104 in oneembodiment is configured to perform synchronized time hopping with thecorresponding synchronized transmitter unit 102 via the communicationlink 103 to obtain the user's detected analyte level.

Referring again to FIG. 1, the data processing terminal 105 may includea personal computer, a portable computer such as a laptop or a handhelddevice (e.g., personal digital assistants (PDAs)), and the like, each ofwhich may be configured for data communication with the receiver via awired or a wireless connection. Additionally, the data processingterminal 105 may further be connected to a data network (not shown) forstoring, retrieving and updating data corresponding to the detectedanalyte level of the user.

Within the scope of the present invention, the data processing terminal105 may include an infusion device such as an insulin infusion pump orthe like, which may be configured to administer insulin to patients, andwhich may be configured to communicate with the receiver unit 104 forreceiving, among others, the measured analyte level. Alternatively, thereceiver unit 104 may be configured to integrate an infusion devicetherein so that the receiver unit 104 is configured to administerinsulin therapy to patients, for example, for administering andmodifying basal profiles, as well as for determining appropriate bolusesfor administration based on, among others, the detected analyte levelsreceived from the transmitter unit 102.

Additionally, the transmitter unit 102, the primary receiver unit 104and the data processing terminal 105 may each be configured forbi-directional wireless communication such that each of the transmitterunit 102, the primary receiver unit 104 and the data processing terminal105 may be configured to communicate (that is, transmit data to andreceive data from) with each other via a wireless communication link.More specifically, the data processing terminal 105 may in oneembodiment be configured to receive data directly from the transmitterunit 102 via the communication link, where the communication link, asdescribed above, may be configured for bi-directional communication.

In this embodiment, the data processing terminal 105 which may includean insulin pump, may be configured to receive the analyte signals fromthe transmitter unit 102, and thus, incorporate the functions of thereceiver unit 104 including data processing for managing the patient'sinsulin therapy and analyte monitoring. In one embodiment, thecommunication link 103 may include one or more of an RF communicationprotocol, an infrared communication protocol, a Bluetooth® enabledcommunication protocol, an 802.11x wireless communication protocol, oran equivalent wireless communication protocol which would allow secure,wireless communication of several units (for example, per HIPAArequirements) while avoiding potential data collision and interference.

FIG. 2 is a block diagram of the transmitter unit of the data monitoringand detection system shown in FIG. 1 in accordance with one embodimentof the present invention. Referring to the Figure, the transmitter unit102 in one embodiment includes an analog interface 201 configured tocommunicate with the sensor 101 (FIG. 1), a user input 202, and atemperature detection section 203, each of which is operatively coupledto a transmitter processor 204 such as a central processing unit (CPU).

Further shown in FIG. 2 are a transmitter serial communication section205 and an RF transmitter 206, each of which is also operatively coupledto the transmitter processor 204. Moreover, a power supply 207 such as abattery is also provided in the transmitter unit 102 to provide thenecessary power for the transmitter unit 102. Additionally, as can beseen from the Figure, clock 208 is provided to, among others, supplyreal time information to the transmitter processor 204.

As can be seen from FIG. 2, the sensor 101 (FIG. 1) is provided fourcontacts, three of which are electrodes—work electrode (W) 210, guardcontact (G) 211, reference electrode (R) 212, and counter electrode (C)213, each operatively coupled to the analog interface 201 of thetransmitter unit 102. In one embodiment, each of the work electrode (W)210, guard contact (G) 211, reference electrode (R) 212, and counterelectrode (C) 213 may be made using a conductive material that is eitherprinted or etched, for example, such as carbon which may be printed, ormetal foil (e.g., gold) which may be etched, or alternatively providedon a substrate material using laser or photolithography.

In one embodiment, a unidirectional input path is established from thesensor 101 (FIG. 1) and/or manufacturing and testing equipment to theanalog interface 201 of the transmitter unit 102, while a unidirectionaloutput is established from the output of the RF transmitter 206 of thetransmitter unit 102 for transmission to the primary receiver unit 104.In this manner, a data path is shown in FIG. 2 between theaforementioned unidirectional input and output via a dedicated link 209from the analog interface 201 to serial communication section 205,thereafter to the processor 204, and then to the RF transmitter 206. Assuch, in one embodiment, via the data path described above, thetransmitter unit 102 is configured to transmit to the primary receiverunit 104 (FIG. 1), via the communication link 103 (FIG. 1), processedand encoded data signals received from the sensor 101 (FIG. 1).Additionally, the unidirectional communication data path between theanalog interface 201 and the RF transmitter 206 discussed above allowsfor the configuration of the transmitter unit 102 for operation uponcompletion of the manufacturing process as well as for directcommunication for diagnostic and testing purposes.

As discussed above, the transmitter processor 204 is configured totransmit control signals to the various sections of the transmitter unit102 during the operation of the transmitter unit 102. In one embodiment,the transmitter processor 204 also includes a memory (not shown) forstoring data such as the identification information for the transmitterunit 102, as well as the data signals received from the sensor 101. Thestored information may be retrieved and processed for transmission tothe primary receiver unit 104 under the control of the transmitterprocessor 204. Furthermore, the power supply 207 may include acommercially available battery.

The transmitter unit 102 is also configured such that the power supplysection 207 is capable of providing power to the transmitter for aminimum of about three months of continuous operation after having beenstored for about eighteen months in a low-power (non-operating) mode. Inone embodiment, this may be achieved by the transmitter processor 204operating in low power modes in the non-operating state, for example,drawing no more than approximately 1 μA of current. Indeed, in oneembodiment, the final step during the manufacturing process of thetransmitter unit 102 may place the transmitter unit 102 in the lowerpower, non-operating state (i.e., post-manufacture sleep mode). In thismanner, the shelf life of the transmitter unit 102 may be significantlyimproved. Moreover, as shown in FIG. 2, while the power supply unit 207is shown as coupled to the processor 204, and as such, the processor 204is configured to provide control of the power supply unit 207, it shouldbe noted that within the scope of the present invention, the powersupply unit 207 is configured to provide the necessary power to each ofthe components of the transmitter unit 102 shown in FIG. 2.

Referring back to FIG. 2, the power supply section 207 of thetransmitter unit 102 in one embodiment may include a rechargeablebattery unit that may be recharged by a separate power supply rechargingunit (for example, provided in the receiver unit 104) so that thetransmitter unit 102 may be powered for a longer period of usage time.Moreover, in one embodiment, the transmitter unit 102 may be configuredwithout a battery in the power supply section 207, in which case thetransmitter unit 102 may be configured to receive power from an externalpower supply source (for example, a battery) as discussed in furtherdetail below.

Referring yet again to FIG. 2, the temperature detection section 203 ofthe transmitter unit 102 is configured to monitor the temperature of theskin near the sensor insertion site. The temperature reading is used toadjust the analyte readings obtained from the analog interface 201. TheRF transmitter 206 of the transmitter unit 102 may be configured foroperation in the frequency band of 315 MHz to 322 MHz, for example, inthe United States. Further, in one embodiment, the RF transmitter 206 isconfigured to modulate the carrier frequency by performing FrequencyShift Keying and Manchester encoding. In one embodiment, the datatransmission rate is 19,200 symbols per second, with a minimumtransmission range for communication with the primary receiver unit 104.

Referring yet again to FIG. 2, also shown is a leak detection circuit214 coupled to the guard contact (G) 211 and the processor 204 in thetransmitter unit 102 of the data monitoring and management system 100.The leak detection circuit 214 in accordance with one embodiment of thepresent invention may be configured to detect leakage current in thesensor 101 to determine whether the measured sensor data are corrupt orwhether the measured data from the sensor 101 is accurate.

FIG. 3 is a block diagram of the receiver/monitor unit of the datamonitoring and management system shown in FIG. 1 in accordance with oneembodiment of the present invention. Referring to FIG. 3, the primaryreceiver unit 104 includes a blood glucose test strip interface 301, anRF receiver 302, an input 303, a temperature detection section 304, anda clock 305, each of which is operatively coupled to a receiverprocessor 307. As can be further seen from the Figure, the primaryreceiver unit 104 also includes a power supply 306 operatively coupledto a power conversion and monitoring section 308. Further, the powerconversion and monitoring section 308 is also coupled to the receiverprocessor 307. Moreover, also shown are a receiver serial communicationsection 309, and an output 310, each operatively coupled to the receiverprocessor 307.

In one embodiment, the test strip interface 301 includes a glucose leveltesting portion to receive a manual insertion of a glucose test strip,and thereby determine and display the glucose level of the test strip onthe output 310 of the primary receiver unit 104. This manual testing ofglucose can be used to calibrate sensor 101. The RF receiver 302 isconfigured to communicate, via the communication link 103 (FIG. 1) withthe RF transmitter 206 of the transmitter unit 102, to receive encodeddata signals from the transmitter unit 102 for, among others, signalmixing, demodulation, and other data processing. The input 303 of theprimary receiver unit 104 is configured to allow the user to enterinformation into the primary receiver unit 104 as needed. In one aspect,the input 303 may include one or more keys of a keypad, atouch-sensitive screen, or a voice-activated input command unit. Thetemperature detection section 304 is configured to provide temperatureinformation of the primary receiver unit 104 to the receiver processor307, while the clock 305 provides, among others, real time informationto the receiver processor 307.

Each of the various components of the primary receiver unit 104 shown inFIG. 3 is powered by the power supply 306 which, in one embodiment,includes a battery. Furthermore, the power conversion and monitoringsection 308 is configured to monitor the power usage by the variouscomponents in the primary receiver unit 104 for effective powermanagement and to alert the user, for example, in the event of powerusage which renders the primary receiver unit 104 in sub-optimaloperating conditions. An example of such sub-optimal operating conditionmay include, for example, operating the vibration output mode (asdiscussed below) for a period of time thus substantially draining thepower supply 306 while the processor 307 (thus, the primary receiverunit 104) is turned on. Moreover, the power conversion and monitoringsection 308 may additionally be configured to include a reverse polarityprotection circuit such as a field effect transistor (FET) configured asa battery activated switch.

The serial communication section 309 in the primary receiver unit 104 isconfigured to provide a bi-directional communication path from thetesting and/or manufacturing equipment for, among others,initialization, testing, and configuration of the primary receiver unit104. Serial communication section 104 can also be used to upload data toa computer, such as time-stamped blood glucose data. The communicationlink with an external device (not shown) can be made, for example, bycable, infrared (IR) or RF link. The output 310 of the primary receiverunit 104 is configured to provide, among others, a graphical userinterface (GUI) such as a liquid crystal display (LCD) for displayinginformation. Additionally, the output 310 may also include an integratedspeaker for outputting audible signals as well as to provide vibrationoutput as commonly found in handheld electronic devices, such as mobiletelephones presently available. In a further embodiment, the primaryreceiver unit 104 also includes an electro-luminescent lamp configuredto provide backlighting to the output 310 for output visual display indark ambient surroundings.

Referring back to FIG. 3, the primary receiver unit 104 in oneembodiment may also include a storage section such as a programmable,non-volatile memory device as part of the processor 307, or providedseparately in the primary receiver unit 104, operatively coupled to theprocessor 307. The processor 307 is further configured to performManchester decoding as well as error detection and correction upon theencoded data signals received from the transmitter unit 102 via thecommunication link 103.

In a further embodiment, the one or more of the transmitter unit 102,the primary receiver unit 104, secondary receiver unit 106, or the dataprocessing terminal/infusion section 105 may be configured to receivethe blood glucose value wirelessly over a communication link from, forexample, a glucose meter. In still a further embodiment, the user orpatient manipulating or using the analyte monitoring system 100 (FIG. 1)may manually input the blood glucose value using, for example, a userinterface (for example, a keyboard, keypad, and the like) incorporatedin the one or more of the transmitter unit 102, the primary receiverunit 104, secondary receiver unit 106, or the data processingterminal/infusion section 105.

Additional detailed description of the continuous analyte monitoringsystem, its various components including the functional descriptions ofthe transmitter are provided in U.S. Pat. No. 6,175,752 issued Jan. 16,2001 entitled “Analyte Monitoring Device and Methods of Use”, and inU.S. patent application Ser. No. 10/745,878 filed Dec. 26, 2003, nowU.S. Pat. No. 7,811,231, entitled “Continuous Glucose Monitoring Systemand Methods of Use”, each assigned to the Assignee of the presentapplication, the disclosures of each of which are incorporated herein byreference for all purposes.

FIGS. 4A-4B illustrate a perspective view and a cross sectional view,respectively of an analyte sensor in accordance with one embodiment ofthe present invention. Referring to FIG. 4A, a perspective view of asensor 400, the major portion of which is above the surface of the skin410, with an insertion tip 430 penetrating through the skin and into thesubcutaneous space 420 in contact with the user's biofluid such asinterstitial fluid. Contact portions of a working electrode 401, areference electrode 402, and a counter electrode 403 can be seen on theportion of the sensor 400 situated above the skin surface 410. Workingelectrode 401, a reference electrode 402, and a counter electrode 403can be seen at the end of the insertion tip 430.

Referring now to FIG. 4B, a cross sectional view of the sensor 400 inone embodiment is shown. In particular, it can be seen that the variouselectrodes of the sensor 400 as well as the substrate and the dielectriclayers are provided in a stacked or layered configuration orconstruction. For example, as shown in FIG. 4B, in one aspect, thesensor 400 (such as the sensor 101 FIG. 1), includes a substrate layer404, and a first conducting layer 401 such as a carbon trace disposed onat least a portion of the substrate layer 404, and which may comprisethe working electrode. Also shown disposed on at least a portion of thefirst conducting layer 401 is a sensing layer 408.

Referring back to FIG. 4B, a first insulation layer such as a firstdielectric layer 405 is disposed or stacked on at least a portion of thefirst conducting layer 401, and further, a second conducting layer 409such as another carbon trace may be disposed or stacked on top of atleast a portion of the first insulation layer (or dielectric layer) 405.As shown in FIG. 4B, the second conducting layer 409 may comprise thereference electrode 402, and in one aspect, may include a layer ofsilver/silver chloride (Ag/AgCl).

Referring still again to FIG. 4B, a second insulation layer 406 such asa dielectric layer in one embodiment may be disposed or stacked on atleast a portion of the second conducting layer 409. Further, a thirdconducting layer 403 which may include carbon trace and that maycomprise the counter electrode 403 may, in one embodiment, be disposedon at least a portion of the second insulation layer 406. Finally, athird insulation layer 407 is disposed or stacked on at least a portionof the third conducting layer 403. In this manner, the sensor 400 may beconfigured in a stacked or layered construction or configuration suchthat at least a portion of each of the conducting layers is separated bya respective insulation layer (for example, a dielectric layer).

Additionally, within the scope of the present invention, some or all ofthe electrodes 401, 402, 403 may be provided on the same side of thesubstrate layer 404 in a stacked construction as described above, oralternatively, may be provided in a co-planar manner such that eachelectrode is disposed on the same plane on the substrate layer 404,however, with a dielectric material or insulation material disposedbetween the conducting layers/electrodes. Furthermore, in still anotheraspect of the present invention, the one or more conducting layers, suchas the electrodes 401, 402, 403, may be disposed on opposing sides ofthe substrate layer 404.

Referring back to the Figures, in one embodiment, the transmitter unit102 (FIG. 1) is configured to detect the current signal from the sensor101 (FIG. 1) and the skin temperature near the sensor 101, which arepreprocessed by, for example, by the transmitter processor 204 (FIG. 2)and transmitted to the receiver unit (for example, the primary receiverunit 104 (FIG. 1)) periodically at a predetermined time interval, suchas for example, but not limited to, once per minute, once every twominutes, once every five minutes, or once every ten minutes.Additionally, the transmitter unit 102 may be configured to performsensor insertion detection and data quality analysis, informationpertaining to which are also transmitted to the receiver unit 104periodically at the predetermined time interval. In turn, the receiverunit 104 may be configured to perform, for example, skin temperaturecompensation as well as calibration of the sensor data received from thetransmitter unit 102.

For example, in one aspect, the transmitter unit 102 may be configuredto oversample the sensor signal at a nominal rate of four samples persecond, which allows the analyte anti-aliasing filter in the transmitterunit 102 to attenuate noise (for example, due to effects resulting frommotion or movement of the sensor after placement) at frequencies above 2Hz. More specifically, in one embodiment, the transmitter processor 204may be configured to include a digital filter to reduce aliasing noisewhen decimating the four Hz sampled sensor data to once per minutesamples for transmission to the receiver unit 104. As discussed infurther detail below, in one aspect, a two stage Kaiser FIR filter maybe used to perform the digital filtering for anti-aliasing. While KaiserFIR filter may be used for digital filtering of the sensor signals,within the scope of the present disclosure, other suitable filters maybe used to filter the sensor signals.

In one aspect, the temperature measurement section 203 of thetransmitter unit 102 may be configured to measure once per minute the onskin temperature near the analyte sensor at the end of the minutesampling cycle of the sensor signal. Within the scope of the presentdisclosure, different sample rates may be used which may include, forexample, but not limited to, measuring the on skin temperature for each30 second periods, each two minute periods, and the like. Additionally,as discussed above, the transmitter unit 102 may be configured to detectsensor insertion, sensor signal settling after sensor insertion, andsensor removal, in addition to detecting for sensor—transmitter systemfailure modes and sensor signal data integrity. Again, this informationis transmitted periodically by the transmitter unit 102 to the receiverunit 104 along with the sampled sensor signals at the predetermined timeintervals.

In a further aspect, the one or more temperature measurements may beobtained or performed at other times during the sampling cycle. Forexample, the one or more temperature measurements may be performed orobtained during the middle of the sampling cycle when the analyterelated data are averaged or otherwise filtered over the cycle.Additionally, in particular embodiments, the one or more temperaturemeasurements or information may be sampled at a faster rate than onceper minute and averaged or otherwise filtered to generate a one minutetemperature sample. Faster sampling rate may provide additional accuracyin the corresponding temperature measurement.

Referring again to the Figures, as the analyte sensor measurements areaffected by the temperature of the tissue around the transcutaneouslypositioned sensor 101, in one aspect, compensation of the temperaturevariations and affects on the sensor signals are provided fordetermining the corresponding glucose value. Moreover, the ambienttemperature around the sensor 101 may affect the accuracy of the on skintemperature measurement and ultimately the glucose value determined fromthe sensor signals. Accordingly, in one aspect, a second temperaturesensor is provided in the transmitter unit 102 away from the on skintemperature sensor (for example, physically away from the temperaturemeasurement section 203 of the transmitter unit 102), so as to providecompensation or correction of the on skin temperature measurements dueto the ambient temperature effects. In this manner, the accuracy of theestimated glucose value corresponding to the sensor signals may beattained.

In one aspect, the processor 204 of the transmitter unit 102 may beconfigured to include the second temperature sensor, which is locatedcloser to the ambient thermal source within the transmitter unit 102. Inother embodiments, the second temperature sensor may be located at adifferent location within the transmitter unit 102 housing where theambient temperature within the housing of the transmitter unit 102 maybe accurately determined.

In a further aspect, each of the first and second temperature sensorsmay be configured to monitor and measure or detect on-skin temperatureas well as ambient temperature. Additionally, within the scope of thepresent disclosure, two or more temperature sensors may be provided tomonitor the on-skin temperature and the ambient temperature.

Referring now to FIG. 5, in one aspect, an ambient temperaturecompensation routine for determining the on-skin temperature level foruse in the glucose estimation determination based on the signalsreceived from the sensor 101 is shown. Referring to FIG. 5, for eachsampled signal from the sensor 101, a corresponding measured temperatureinformation is received (510), for example, by the processor 204 fromthe temperature measurement section 203 (which may include, for example,a thermister provided in the transmitter unit 102). In addition, asecond temperature measurement is obtained (520), for example, includinga determination of the ambient temperature level using a secondtemperature sensor provided within the housing the transmitter unit 102.

In one aspect, based on a predetermined ratio of thermal resistancesbetween the temperature measurement section 203 and the secondtemperature sensor (located, for example, within the processor 204 ofthe transmitter unit 102), and between the temperature measurementsection 203 and the skin layer on which the transmitter unit 102 isplaced and coupled to the sensor 101, ambient temperature compensationmay be performed (530), to determine the corresponding ambienttemperature compensated on skin temperature level (540). In oneembodiment, the predetermined ratio of the thermal resistances may beapproximately 0.2. However, within the scope of the present invention,this thermal resistance ratio may vary according to the design of thesystem, for example, based on the size of the transmitter unit 102housing, the location of the second temperature sensor within thehousing of the transmitter unit 102, and the like.

With the ambient temperature compensated on-skin temperatureinformation, the corresponding glucose value from the sampled analytesensor signal may be determined.

Referring again to FIG. 2, the processor 204 of the transmitter unit 102may include a digital anti-aliasing filter. Using analog anti-aliasingfilters for a one minute measurement data sample rate would require alarge capacitor in the transmitter unit 102 design, and which in turnimpacts the size of the transmitter unit 102. As such, in one aspect,the sensor signals may be oversampled (for example, at a rate of 4 timesper second), and then the data is digitally decimated to derive aone-minute sample rate.

As discussed above, in one aspect, the digital anti-aliasing filter maybe used to remove, for example, signal artifacts or otherwiseundesirable aliasing effects on the sampled digital signals receivedfrom the analog interface 201 of the transmitter unit 102. For example,in one aspect, the digital anti-aliasing filter may be used toaccommodate decimation of the sensor data from approximately four Hzsamples to one-minute samples. In one aspect, a two stage FIR filter maybe used for the digital anti-aliasing filter, and which includesimproved response time, pass band and stop band properties.

Referring to FIG. 6, a routine for digital anti-aliasing filtering isshown in accordance with one embodiment. As shown, in one embodiment, ateach predetermined time period such as every minute, the analog signalfrom the analog interface 201 corresponding to the monitored analytelevel received from the sensor 101 (FIG. 1) is sampled (610). Forexample, at every minute, in one embodiment, the signal from the analoginterface 201 is over-sampled at approximately 4 Hz. Thereafter, thefirst stage digital filtering on the over-sampled data is performed(620), where, for example, a 1/6 down-sampling from 246 samples to 41samples is performed, and the resulting 41 samples is furtherdown-sampled at the second stage digital filtering (630) such that, forexample, a 1/41 down-sampling is performed from 41 samples (from thefirst stage digital filtering), to a single sample. Thereafter, thefilter is reset (640), and the routine returns to the beginning for thenext minute signal received from the analog interface 201.

While the use of FIR filter, and in particular the use of Kaiser FIRfilter, is within the scope of the present invention, other suitablefilters, such as FIR filters with different weighting schemes or IIRfilters, may be used.

Referring yet again to the Figures, the transmitter unit 102 may beconfigured in one embodiment to periodically perform data quality checksincluding error condition verifications and potential error conditiondetections, and also to transmit the relevant information related to oneor more data quality, error condition or potential error conditiondetection to the receiver unit 104 with the transmission of themonitored sensor data. For example, in one aspect, a state machine maybe used in conjunction with the transmitter unit 102 and which may beconfigured to be updated four times per second, the results of which aretransmitted to the receiver unit 104 every minute.

In particular, using the state machine, the transmitter unit 102 may beconfigured to detect one or more states that may indicate when a sensoris inserted, when a sensor is removed from the user, and further, mayadditionally be configured to perform related data quality checks so asto determine when a new sensor has been inserted or transcutaneouslypositioned under the skin layer of the user and has settled in theinserted state such that the data transmitted from the transmitter unit102 does not compromise the integrity of signal processing performed bythe receiver unit 104 due to, for example, signal transients resultingfrom the sensor insertion.

That is, when the transmitter unit 102 detects low or no signal from thesensor 101, which is followed by detected signals from the sensor 101that is above a given signal, the processor 204 may be configured toidentify such transition in the monitored signal levels and associatewith a potential sensor insertion state. Alternatively, the transmitterunit 102 may be configured to detect the signal level above the anotherpredetermined threshold level, which is followed by the detection of thesignal level from the sensor 101 that falls below the predeterminedthreshold level. In such a case, the processor 204 may be configured toassociate or identify such transition or condition in the monitoredsignal levels as a potential sensor removal state.

Accordingly, when either of potential sensor insertion state orpotential sensor removal state is detected by the transmitter unit 102,this information is transmitted to the receiver unit 104, and in turn,the receiver unit 104 may be configured to prompt the user forconfirmation of either of the detected potential sensor related state.In another aspect, the sensor insertion state or potential sensorremoval state may be detected or determined by the receiver unit 104based on one or more signals received from the transmitter unit 102. Forexample, similar to an alarm condition or a notification to the user,the receiver unit 104 may be configured to display a request or a prompton the display or an output unit of the receiver unit 104 a text and/orother suitable notification message to inform the user to confirm thestate of the sensor 101.

For example, the receiver unit 104 may be configured to display thefollowing message: “New Sensor Inserted?” or a similar notification inthe case where the receiver unit 104 receives one or more signals fromthe transmitter unit 102 associated with the detection of the signallevel below the predetermined threshold level for the predefined periodof time, followed by the detection of the signal level from the sensor101 above another predetermined threshold level for another predefinedperiod of time. Additionally, the receiver unit 104 may be configured todisplay the following message: “Sensor Removed?” or a similarnotification in the case where the receiver unit 104 received one ormore signals from the transmitter unit 102 associated with the detectionof the signal level from the sensor 101 that is above the anotherpredetermined threshold level for the another predefined period of time,which is followed by the detection of the signal level from the sensor101 that falls below the predetermined threshold level for thepredefined period of time.

Based on the user confirmation received, the receiver unit 104 may befurther configured to execute or perform additional related processingand routines in response to the user confirmation or acknowledgement.For example, when the user confirms, using the user interfaceinput/output mechanism of the receiver unit 104, for example, that a newsensor has been inserted, the receiver unit 104 may be configured toinitiate new sensor insertion related routines including, such as, forexample, sensor calibration routine including, for example, calibrationtimer, sensor expiration timer and the like. Alternatively, when theuser confirms or it is determined that the sensor 101 is not properlypositioned or otherwise removed from the insertion site, the receiverunit 104 may be accordingly configured to perform related functions suchas, for example, stop displaying of the glucose values/levels, ordeactivating the alarm monitoring conditions.

On the other hand, in response to the potential sensor insertionnotification generated by the receiver unit 104, if the user confirmsthat no new sensor has been inserted, then the receiver unit 104 in oneembodiment is configured to assume that the sensor 101 is in acceptableoperational state, and continues to receive and process signals from thetransmitter unit 102.

In this manner, in cases, for example, when there is momentary movementor temporary dislodging of the sensor 101 from the initially positionedtranscutaneous state, or when one or more of the contact points betweensensor 101 and the transmitter unit 102 are temporarily disconnected,but otherwise, the sensor 101 is operational and within its useful life,the routine above provides an option to the user to maintain the usageof the sensor 101, and no replacing the sensor 101 prior to theexpiration of its useful life. In this manner, in one aspect, falsepositive indications of sensor 101 failure may be identified andaddressed.

For example, FIG. 7 is a flowchart illustrating actual or potentialsensor insertion or removal detection routine in accordance with oneembodiment of the present invention. Referring to the Figure, thecurrent analyte related signal is first compared to a predeterminedsignal characteristic (710). In one aspect, the predetermined signalcharacteristic may include one of a signal level transition from below afirst predetermined level (for example, but not limited to, 18 ADC(analog to digital converter) counts) to above the first predeterminedlevel, a signal level transition from above a second predetermined level(for example, but not limited to, 9 ADC counts) to below the secondpredetermined level, a transition from below a predetermined signal rateof change threshold to above the predetermined signal rate of changethreshold, and a transition from above the predetermined signal rate ofchange threshold to below the predetermined signal rate of changethreshold.

Referring back to the Figure, after comparing the current analyterelated signal to the predetermined signal characteristic (710), acorresponding operational state associated with an analyte monitoringdevice is determined (720). Referring again to FIG. 7, after determiningthe corresponding operational state associated with the analytemonitoring device (720), the current analyte related signal may becompared to a prior signal associated with the analyte level (730) andan output data associated with the operational state is generated (740).

In this manner, in one aspect of the present invention, based on atransition state of the received analyte related signals, it may bepossible to determine the state of the analyte sensor, and based onwhich, the user or the patient to confirm whether the analyte sensor isin the desired or proper position, has been temporarily dislocated, orotherwise, removed from the desired insertion site so as to require anew analyte sensor.

In this manner, in one aspect, when the monitored signal from the sensor101 (FIG. 1) crosses a transition level (for example, from no or lowsignal level to a high signal level, or vice versa), the transmitterunit 102 may be configured to generate an appropriate output dataassociated with the sensor signal transition, for transmission to thereceiver unit 104 (FIG. 1). Additionally, as discussed in further detailbelow, in another embodiment, the determination of whether the sensor101 has crossed a transition level may be determined by thereceiver/monitor unit 104/106 based, at least in part on the one or moresignals received from the transmitter unit 102.

FIG. 8 is a flowchart illustrating receiver unit processingcorresponding to the actual or potential sensor insertion or removaldetection routine of FIG. 7 in accordance with one embodiment of thepresent invention. Referring now to FIG. 8, when the receiver unit 104receives the generated output data from the transmitter unit 102 (810),a corresponding operation state is associated with the received outputdata (820), for example, related to the operational state of the sensor101. Moreover, a notification associated with the sensor operation stateis generated and output to the user on the display unit or any othersuitable output segment of the receiver unit 104 (830). When a userinput signal is received in response to the notification associated withthe sensor state operation state (840), the receiver unit 104 isconfigured to execute one or more routines associated with the receiveduser input signal (850).

That is, as discussed above, in one aspect, if the user confirms thatthe sensor 101 has been removed, the receiver unit 104 may be configuredto terminate or deactivate alarm monitoring and glucose displayingfunctions. On the other hand, if the user confirms that a new sensor 101has been positioned or inserted into the user, then the receiver unit104 may be configured to initiate or execute routines associated withthe new sensor insertion, such as, for example, calibration procedures,establishing calibration timer, and establishing sensor expirationtimer.

In a further embodiment, based on the detected or monitored signaltransition, the receiver/monitor unit may be configured to determine thecorresponding sensor state without relying upon the user input orconfirmation signal associated with whether the sensor is dislocated orremoved from the insertion site, or otherwise, operating properly.

FIG. 9 is a flowchart illustrating data processing corresponding to theactual or potential sensor insertion or removal detection routine inaccordance with another embodiment of the present invention. Referringto FIG. 9, a current analyte related signal is received and compared toa predetermined signal characteristic (910). Thereafter, an operationalstate associated with an analyte monitoring device such as, for example,the sensor 101 (FIG. 1) is retrieved (920) from a storage unit orotherwise resident in, for example, a memory of the receiver/monitorunit. Additionally, a prior analyte related signal is also retrievedfrom the storage unit, and compared to the current analyte relatedsignal received (930). An output data is generated which is associatedwith the operational state (940), and which at least in part is based onthe one or more of the received current analyte related signal and theretrieved prior analyte related signal.

Referring again to FIG. 9, when the output data is generated, acorresponding user input command or signal is received in response tothe generated output data (950), and which may include one or more of aconfirmation, verification, or rejection of the operational staterelated to the analyte monitoring device.

FIG. 10 is a flowchart illustrating a concurrent passive notificationroutine in the data receiver/monitor unit of the data monitoring andmanagement system of FIG. 1 in accordance with one embodiment of thepresent invention. Referring to FIG. 10, a predetermined routine isexecuted for a predetermined time period to completion (1010). Duringthe execution of the predetermined routine, an alarm condition isdetected (1020), and when the alarm or alert condition is detected, afirst indication associated with the detected alarm or alert conditionis output concurrent to the execution of the predetermined routine(1030).

That is, in one embodiment, when a predefined routine is being executed,and an alarm or alert condition is detected, a notification is providedto the user or patient associated with the detected alarm or alertcondition, but which does not interrupt or otherwise disrupt theexecution of the predefined routine. Referring back to FIG. 10, upontermination of the predetermined routine, another output or secondindication associated with the detected alarm condition is output ordisplayed (1040).

More specifically, in one aspect, the user interface notificationfeature associated with the detected alarm condition is output to theuser only upon the completion of an ongoing routine which was in theprocess of being executed when the alarm condition is detected. Asdiscussed above, when such alarm condition is detected during theexecution of a predetermined routine, a temporary alarm notificationsuch as, for example, a backlight indicator, a text output on the userinterface display or any other suitable output indication may beprovided to alert the user or the patient of the detected alarmcondition substantially in real time, but which does not disrupt anongoing routine.

Within the scope of the present invention, the ongoing routine or thepredetermined routine being executed may include one or more ofperforming a finger stick blood glucose test (for example, for purposesof periodically calibrating the sensor 101), or any other processes thatinterface with the user interface, for example, on the receiver/monitorunit 104/106 (FIG. 1) including, but not limited to the configuration ofdevice settings, review of historical data such as glucose data, alarms,events, entries in the data log, visual displays of data includinggraphs, lists, and plots, data communication management including RFcommunication administration, data transfer to the data processingterminal 105 (FIG. 1), or viewing one or more alarm conditions with adifferent priority in a preprogrammed or determined alarm ornotification hierarchy structure.

In this manner, in one aspect of the present invention, the detection ofone or more alarm conditions may be presented or notified to the user orthe patient, without interrupting or disrupting an ongoing routine orprocess in, for example, the receiver/monitor unit 104/106 of the datamonitoring and management system 100 (FIG. 1).

A method in accordance with one embodiment includes detecting a firsttemperature related signal from a first source, detecting a secondtemperature related signal from a second source, the second sourcelocated at a predetermined distance from the first source, andestimating an analyte temperature related signal based on the first andsecond detected temperature signals.

The first source in one aspect may be located substantially in closeproximity to a transcutaneously positioned analyte sensor, and morespecifically, in one embodiment, the first source may be locatedapproximately 0.75 inches from the analyte sensor.

In a further embodiment, the analyte temperature related signal may beestimated based on a predetermined value associated with the detectedfirst and second temperature related signals, where the predeterminedvalue may include a ratio of thermal resistances associated with thefirst and second sources.

The method in a further aspect may include determining a glucose valuebased on the estimated analyte temperature related signal and amonitored analyte level.

The second temperature related signal in yet another aspect may berelated to an ambient temperature source.

An apparatus in a further embodiment may include a housing, an analytesensor coupled to the housing and transcutaneously positionable under askin layer of a user, a first temperature detection unit coupled to thehousing configured to detect a temperature associated with the analytesensor, and a second temperature detection unit provided in the housingand configured to detect an ambient temperature.

The one or more of the first temperature detection unit or the secondtemperature detection unit may include one or more of a thermistor, asemiconductor temperature sensor, or a resistance temperature detector(RTD).

The apparatus in a further aspect may also include a processor, where atleast a portion of the second temperature detection unit may be providedwithin the processor. In one aspect, the processor may be providedwithin same housing as the one or more first or second temperaturedetection units.

In another embodiment, the processor may be configured to receive thetemperature associated with the analyte sensor, the ambient temperature,and an analyte related signal from the analyte sensor, and also, theprocessor may be configured to estimate an analyte temperature relatedsignal based on the temperature associated with the analyte sensor, andthe ambient temperature.

Also, the processor may be configured to determine a glucose value basedon the estimated analyte temperature related signal and an analyterelated signal from the analyte sensor.

In still another aspect, the analyte temperature related signal may beestimated based on a predetermined value associated with the detectedtemperature associated with the analyte sensor, and the ambienttemperature, where the predetermined value may include a ratio ofthermal resistances associated with the temperature associated with theanalyte sensor, and the ambient temperature.

Alternatively, the predetermined value in still another aspect may bevariable based on an error feedback signal associated with the monitoredanalyte level by the analyte sensor, where the error feedback signal maybe associated with a difference between a blood glucose reference valueand the analyte sensor signal.

The apparatus may also include a transmitter unit configured to transmitone or more signals associated with the detected temperature associatedwith the analyte sensor, detected ambient temperature, an analyterelated signal from the analyte sensor, analyte temperature relatedsignal based on the temperature associated with the analyte sensor, andthe ambient temperature, or a glucose value based on the estimatedanalyte temperature related signal and the analyte related signal fromthe analyte sensor.

The transmitter unit may include an RF transmitter.

A system in accordance with still another embodiment may include a datareceiver configured to receive a first temperature related signal from afirst source, a second temperature related signal from a second source,the second source located at a predetermined distance from the firstsource, and a processor operatively coupled to the data receiver, andconfigured to estimate an analyte temperature related signal based onthe first and second detected temperature signals.

An apparatus in accordance with a further embodiment includes a digitalfilter unit including a first filter stage and a second filter stage,the digital filter unit configured to receive a sampled signal, wherethe first filter stage is configured to filter the sampled signal basedon a first predetermined filter characteristic to generate a firstfilter stage output signal, and further, where the second filter stageis configured to filter the first filter stage output signal based on asecond predetermined filter characteristic to generate an output signalassociated with a monitored analyte level.

The sampled signal may include an over-sampled signal at a frequency ofapproximately 4 Hz.

The digital filter unit may include one of a Finite Impulse Response(FIR) filter, or an Infinite Impulse Response (IIR) filter.

The first and the second filter stages may include a respective firstand second down sampling filter characteristics.

Also, the one or more of the first and second filter stages may includedown sampling the sampled signal or the first filter stage outputsignal, respectively, where the received sampled signal may beassociated with the monitored analyte level of a user.

In another aspect, the digital filter unit may be configured to receivethe sampled signal at a predetermined time interval.

The predetermined time interval in one aspect may include one ofapproximately 30 seconds approximately one minute, approximately twominutes, approximately five minutes, or any other suitable time periods.

A method in accordance with yet another embodiment includes receiving asampled signal associated with a monitored analyte level of a user,performing a first stage filtering based on the received sampled signalto generate a first stage filtered signal, performing a second stagefiltering based on the generated first stage filtered signal, andgenerating a filtered sampled signal.

The sampled signal may include an over-sampled signal at a frequency ofapproximately 4 Hz, and also, where the first and the second stagefiltering may include a respective first and second down sampling basedon one or more filter characteristics.

The received sampled signal in one aspect may be periodically receivedat a predetermined time interval, where the predetermined time intervalmay include one of approximately 30 seconds, approximately one minute,approximately two minutes, or approximately five minutes.

A method in still another embodiment may include receiving a signalassociated with an analyte level of a user, determining whether thereceived signal deviates from a predetermined signal characteristic,determining an operational state associated with an analyte monitoringdevice, comparing a prior signal associated with the analyte level ofthe user to the received signal, generating an output data associatedwith the operational state of the analyte monitoring device based on oneor more of the received signal and the prior signal.

The predetermined signal characteristic in one embodiment may include asignal level transition from below a first predetermined level to abovethe first predetermined level, a signal level transition from above asecond predetermined level to below the second predetermined threshold,a transition from below a predetermined signal rate of change thresholdto above the predetermined signal rate of change threshold, or atransition from above the predetermined signal rate of change thresholdto below the predetermined signal rate of change threshold.

In one aspect, the first predetermined level and the secondpredetermined level each may include one of approximately 9 ADC countsor approximately 18 ADC counts, or any other suitable signal levels oranalog to digital converter (ADC) counts that respectively represent orcorrespond to a no sensor signal state, a sensor signal state, or thelike.

The predetermine signal characteristic may include in one aspect, atransition from below a predetermined level to above and wherein thesignal is maintained above the predetermined level for a predeterminedperiod of time, where the predetermined period of time may include oneof approximately 10 seconds, 30 seconds, or less than 30 seconds, orgreater than 30 seconds, or any other suitable time periods.

In a further aspect, the operational state may include a no detectedsensor state, or a sensor presence state.

The output data in one embodiment may include a user notification alert.

Further, the output data may include an indicator to start one or moreprocessing timers associated with a respective one or more dataprocessing routines, where the one or more processing timers may includea respective one of a calibration timer, or a sensor expiration timer.

The method may include receiving a user input data based on the outputdata, where the user input data may include a user confirmation of oneof the change in operational state or no change in operational state.

The method may further include modifying the operational state, wherethe operational state may be modified based on one of the received userinput data, or based on the generated output data.

The method may include presenting the output data, where presenting theoutput data may include one or more of visually presenting the outputdata, audibly presenting the output data, vibratorily presenting theoutput data, or one or more combinations thereof.

The analyte level may include glucose level of the user.

The operational state may include one of an analyte sensor removalstate, an analyte sensor insertion state, an analyte sensor dislocationstate, an analyte sensor insertion with an associated transient signalstate, or an analyte sensor insertion with an associated stabilizedsignal state.

An apparatus in still yet another embodiment may include a dataprocessing unit including a data processor configured to determinewhether a received signal associated with an analyte level of a userdeviates from a predetermined signal characteristic, determine anoperational state associated with an analyte monitoring device, comparea prior signal associated with the analyte level of the user to thereceived signal, and generate an output data associated with theoperational state of the analyte monitoring device based on one or moreof the received signal or the prior signal.

The data processing unit may include a communication unit operativelycoupled to the data processor and configured to communicate one or moreof the received signal, the prior signal, and the output data associatedthe operational state of the analyte monitoring device.

The communication unit may include one of an RF transmitter, an RFreceiver, an infrared data communication device, a Bluetooth® datacommunication device, or a Zigbee® data communication device.

The data processing unit may include a storage unit operatively coupledto the data processor to store one or more of the received signalassociated with the analyte level, the predetermined signalcharacteristic, the operational state associated with the analytemonitoring device, the prior signal associated with the analyte level ofthe user, or the output data associated with the operational state ofthe analyte monitoring device.

A method in accordance with still yet a further embodiment may includereceiving a signal associated with an analyte level of a user,determining whether the received signal deviates from a predeterminedsignal characteristic, determining an operational state associated withan analyte monitoring device, comparing a prior signal associated withthe analyte level of the user to the received signal, presenting anoutput data associated with the operational state of the analytemonitoring device based at least in part on one or more of the receivedsignal or the prior signal, and receiving a user input data based on thepresented output data.

In still another aspect, the predetermined signal characteristic mayinclude a signal level transition from below a first predetermined levelto above the first predetermined level, a signal level transition fromabove a second predetermined level to below the second predeterminedlevel, a transition from below a predetermined signal rate of changethreshold to above the predetermined signal rate of change threshold,and a transition from above the predetermined signal rate of changethreshold to below the predetermined signal rate of change threshold,and further, where the first predetermined level and the secondpredetermined level each may include one of approximately 9 ADC countsor approximately 18 ADC counts, or other predetermined ADC counts orsignal levels.

The predetermine signal characteristic in another aspect may include atransition from below a predetermined level to above and wherein thesignal is maintained above the predetermined level for a predeterminedperiod of time which may include, for example, but not limited to,approximately 10 seconds, 30 seconds, or less than 30 seconds, orgreater than 30 seconds.

Further, the operational state may include a no detected sensor state,or a sensor presence state.

Moreover, the output data may include a user notification alert.

The output data may include an indicator to start one or more processingtimers associated with a respective one or more data processingroutines, where the one or more processing timers may include arespective one of a calibration timer, or a sensor expiration timer.

In another aspect, the user input data may include a user confirmationof one of the change in operational state or no change in operationalstate.

The method may include modifying the operational state based on, forexample, one of the received user input data, or based on the generatedoutput data.

Additionally, presenting the output data may include one or more ofvisually presenting the output data, audibly presenting the output data,vibratorily presenting the output data, or one or more combinationsthereof.

Also, the operational state may include one of an analyte sensor removalstate, an analyte sensor insertion state, an analyte sensor dislocationstate, an analyte sensor insertion with an associated transient signalstate, or an analyte sensor insertion with an associated stabilizedsignal state.

A data processing device in accordance with one embodiment may include auser interface unit, and a data processor operatively coupled to theuser interface unit, the data processor configured to receive a signalassociated with an analyte level of a user, determine whether thereceived signal deviates from a predetermined signal characteristic,determine an operational state associated with an analyte monitoringdevice, compare a prior signal associated with the analyte level of theuser to the received signal, present in the user interface unit anoutput data associated with the operational state of the analytemonitoring device based at least in part on one or more of the receivedsignal or the prior signal, and to receive a user input data from theuser interface unit based on the presented output data.

The user interface unit in one aspect may include one or more of a userinput unit, a visual display unit, an audible output unit, a vibratoryoutput unit, or a touch sensitive user input unit.

In one embodiment, the device may include a communication unitoperatively coupled to the data processor and configured to communicateone or more of the received signal, the prior signal, and the outputdata associated with the operational state of the analyte monitoringdevice, where the communication unit may include, for example, but notlimited to one of an RF transmitter, an RF receiver, an infrared datacommunication device, a Bluetooth® data communication device, a Zigbee®data communication device, or a wired connection.

The data processing device may include a storage unit operativelycoupled to the data processor to store one or more of the receivedsignal associated with the analyte level, the predetermined signalcharacteristic, the operational state associated with the analytemonitoring device, the prior signal associated with the analyte level ofthe user, or the output data associated with the operational state ofthe analyte monitoring device.

A method in accordance with still yet another embodiment may includeexecuting a predetermined routine associated with an operation of ananalyte monitoring device, detecting one or more predefined alarmconditions associated with the analyte monitoring device, outputting afirst indication associated with the detected one or more predefinedalarm conditions during the execution of the predetermined routine,outputting a second indication associated with the detected one or morepredefined alarm conditions after the execution of the predeterminedroutine, where the predetermined routine is executed withoutinterruption during the outputting of the first indication.

In one aspect, the predetermined routine may include one or moreprocesses associated with performing a blood glucose assay, one or moreconfiguration settings, analyte related data review or analysis, datacommunication routine, calibration routine, or reviewing a higherpriority alarm condition notification compared to the predeterminedroutine, or any other process or routine that requires the userinterface.

Moreover, in one aspect, the first indication may include one or more ofa visual, audible, or vibratory indicators.

Further, the second indication may include one or more of a visual,audible, or vibratory indicators.

In one aspect, the first indication may include a temporary indicator,and further, and the second indication may include a predetermined alarmassociated with detected predefined alarm condition.

In still another aspect, the first indication may be active during theexecution of the predetermined routine, and may be inactive at the endof the predetermined routine.

Further, the second indication in a further aspect may be active at theend of the predetermined routine.

Moreover, each of the first indication and the second indication mayinclude one or more of a visual text notification alert, a backlightindicator, a graphical notification, an audible notification, or avibratory notification.

The predetermined routine may be executed to completion withoutinterruption.

An apparatus in accordance with still another embodiment may include auser interface, and a data processing unit operatively coupled to theuser interface, the data processing unit configured to execute apredetermined routine associated with an operation of an analytemonitoring device, detect one or more predefined alarm conditionsassociated with the analyte monitoring device, output on the userinterface a first indication associated with the detected one or morepredefined alarm conditions during the execution of the predeterminedroutine, and output on the user interface a second indication associatedwith the detected one or more predefined alarm conditions after theexecution of the predetermined routine, wherein the predeterminedroutine is executed without interruption during the outputting of thefirst indication.

The predetermined routine may include one or more processes associatedwith performing a blood glucose assay, one or more configurationsettings, analyte related data review or analysis, data communicationroutine, calibration routine, or reviewing a higher priority alarmcondition notification compared to the predetermined routine.

The first indication or the second indication or both, in one aspect mayinclude one or more of a visual, audible, or vibratory indicators outputon the user interface.

In addition, the first indication may include a temporary indicator, andfurther, wherein the second indication includes a predetermined alarmassociated with a detected predefined alarm condition.

Also, the first indication may be output on the user interface duringthe execution of the predetermined routine, and is not output on theuser interface at or prior to the end of the predetermined routine.

Additionally, the second indication may be active at the end of thepredetermined routine.

In another aspect, each of the first indication and the secondindication may include a respective one or more of a visual textnotification alert, a backlight indicator, a graphical notification, anaudible notification, or a vibratory notification, configured to outputon the user interface.

Various other modifications and alterations in the structure and methodof operation of this invention will be apparent to those skilled in theart without departing from the scope and spirit of the invention.Although the invention has been described in connection with specificpreferred embodiments, it should be understood that the invention asclaimed should not be unduly limited to such specific embodiments. It isintended that the following claims define the scope of the presentinvention and that structures and methods within the scope of theseclaims and their equivalents be covered thereby.

What is claimed is:
 1. A method, comprising: detecting a firsttemperature related signal from a first temperature sensor, the firsttemperature related signal corresponding to a temperature of skin withina predetermined distance of a transcutaneously positioned analytesensor, wherein the analyte sensor includes a plurality of electrodescomprising at least one working electrode, the working electrodeincluding an analyte-responsive enzyme and a mediator, and at least oneof the analyte-responsive enzyme and the mediator is chemically bondedto a polymer disposed on the working electrode, and further wherein atleast one of the analyte-responsive enzyme and the mediator iscrosslinked with the polymer; detecting a second temperature relatedsignal from a second temperature sensor, the second temperature relatedsignal corresponding to an ambient temperature in a housing of a datacommunication device, wherein the data communication device isoperatively coupled to the analyte sensor and wherein the secondtemperature sensor is located at a predetermined distance from the firsttemperature sensor; estimating an analyte temperature related signalbased on the first and second detected temperature related signals; anddetermining an analyte level in interstitial fluid based on theestimated analyte temperature related signal and a sensor signal fromthe transcutaneously positioned analyte sensor, wherein the firsttemperature related signal corresponding to the temperature of skin andthe second temperature related signal corresponding to the ambienttemperature in the housing are measured at a predetermined time of asampling cycle of the analyte sensor; wherein the analyte temperaturerelated signal is estimated based on a predetermined value associatedwith the detected first and second temperature related signals; andwherein the predetermined value includes a ratio of thermal resistancesassociated with the first and second temperature sensors.
 2. The methodof claim 1, wherein the predetermined time of the sampling cycle of theanalyte sensor is the end of the sampling cycle of the analyte sensor.3. The method of claim 1, further comprising determining an averagetemperature from a plurality of temperatures measured during thesampling cycle of the analyte sensor.
 4. The method of claim 1, whereinthe predetermined time of the sampling cycle of the analyte sensor isthe middle of the sampling cycle of the analyte sensor.
 5. The method ofclaim 1, further comprising detecting when the analyte sensor has beeninserted into a user, and detecting when the analyte sensor has beenremoved from the user.
 6. The method of claim 1, wherein the secondtemperature sensor is located within a transmitter unit housed in asensor assembly.
 7. An apparatus, comprising: a housing; an analytesensor coupled to the housing and transcutaneously positionable under askin layer of a user, wherein the analyte sensor includes a plurality ofelectrodes comprising at least one working electrode, the workingelectrode including an analyte-responsive enzyme and a mediator, and atleast one of the analyte-responsive enzyme and the mediator ischemically bonded to a polymer disposed on the working electrode, andfurther wherein at least one of the analyte-responsive enzyme and themediator is crosslinked with the polymer; a first temperature detectionunit coupled to the housing and configured to detect a temperature ofskin within a predetermined distance of an insertion point of theanalyte sensor; a second temperature detection unit provided in thehousing and configured to detect an ambient temperature within thehousing; and a processor configured to estimate an analyte temperaturerelated signal based on the temperature of the skin and the ambienttemperature within the housing, wherein the processor is furtherconfigured to receive an analyte related signal in interstitial fluidfrom the analyte sensor, and wherein the processor is further configuredto determine an analyte value in interstitial fluid based on theestimated analyte temperature related signal and the analyte relatedsignal in interstitial fluid; wherein the analyte temperature relatedsignal is estimated based on a predetermined value associated with thedetected temperature of the skin and the ambient temperature within thehousing; and wherein the predetermined value includes a ratio of thermalresistances associated with the temperature of the skin and the ambienttemperature within the housing.
 8. The apparatus of claim 7, wherein oneor more of the first temperature detection unit or the secondtemperature detection unit includes one or more of a thermistor, asemiconductor temperature sensor, or a resistance temperature detector(RTD).
 9. The apparatus of claim 7, wherein the predetermined value isvariable based on an error feedback signal associated with a monitoredanalyte level by the analyte sensor.
 10. The apparatus of claim 9,wherein the error feedback signal is associated with a differencebetween a blood glucose reference value and an analyte related signalfrom the analyte sensor.
 11. The apparatus of claim 7, further includinga data communication device configured to communicate one or moresignals associated with the detected temperature of the skin, thedetected ambient temperature within the housing, the analyte relatedsignal from the analyte sensor, the analyte temperature related signalbased on the temperature of the skin and the ambient temperature withinthe housing, or a glucose value based on the estimated analytetemperature related signal and the analyte related signal from theanalyte sensor.
 12. The apparatus of claim 11, wherein the datacommunication device is an RF transmitter.
 13. The apparatus of claim 7,wherein the first temperature detection unit detects the temperature ofskin at a predetermined time of a sampling cycle of the analyte sensor.14. The apparatus of claim 7, wherein the second temperature detectionunit is provided in a transmitter unit within the housing.
 15. A system,comprising: a data receiver configured to receive a first temperaturerelated signal from a first temperature sensor, the first temperaturerelated signal corresponding to a temperature of skin within apredetermined distance of a transcutaneously positioned analyte sensor,a second temperature related signal from a second temperature sensor,the second temperature related signal corresponding to an ambienttemperature in a housing of a data communication device, wherein thedata communication device is operatively coupled to the analyte sensorand wherein the second temperature sensor is located at a predetermineddistance from the first temperature sensor; and a processor operativelycoupled to the data receiver, and configured to estimate an analytetemperature related signal based on the first and second detectedtemperature signals, wherein the processor is further configured toreceive an analyte related signal in interstitial fluid from the analytesensor, and wherein the processor is further configured to determine ananalyte value in interstitial fluid based on the estimated analytetemperature related signal and the analyte related signal ininterstitial fluid; wherein the analyte temperature related signal isestimated based on a predetermined value associated with the detectedtemperature of the skin and the ambient temperature in the housing;wherein the predetermined value includes a ratio of thermal resistancesassociated with the temperature of the skin and the ambient temperaturein the housing; and wherein the analyte sensor includes a plurality ofelectrodes comprising at least one working electrode, the workingelectrode including an analyte-responsive enzyme and a mediator, and atleast one of the analyte-responsive enzyme and the mediator ischemically bonded to a polymer disposed on the working electrode, andfurther wherein at least one of the analyte-responsive enzyme and themediator is crosslinked with the polymer.
 16. The system of claim 15,wherein the second temperature sensor is located within a transmitterunit housed in a sensor assembly.